Engineering Research and Technology Development on the Space Station (1996)

Discerning the needs of customers and then meeting them has become a central tenet of American business. To facilitate the participation of academia and industry—key customers for the services the space station will provide—in ERTD on the ISS, this idea must also gain greater acceptance at NASA. External experimenters currently must deal with a series of NASA procedures and technical interface requirements that add little value but that can cause significant delays and increase the cost of experimentation. To be sure, the goals that have motivated these procedures and interface requirements—crew safety and operational efficiency—are plainly valid. Nevertheless, NASA should be able to achieve these objectives fully, yet in a way that does not discourage experimenters. Striking the proper balance will require modification of these procedures and requirements, with a focus on the customer.

The procedures that must be carried out by industry, university, and NASA researchers as they prepare experiments for space flight could be modified in a number of areas to facilitate ERTD experimentation (as well as other types of research) on the ISS. These include (1) providing advice and assistance in preparing experiments for the ISS, and (2) standardizing the integration process. The focus here is on procedures for experiments funded primarily by the government. Chapter 5 suggests a different set of procedures for commercial ERTD.

Although NASA program offices are the primary sources of funding for in-space experiments, the NASA centers (primarily Goddard, Marshall, Langley,

Lewis, and Johnson) play the largest role in working with researchers and shepherding experiments from concept to flight in space. Typically, however, the centers do not appear to view outside experimenters as “customers” whose needs must be met but as contractors who must be supervised to ensure that their experiments meet certain requirements. Testing, documentation, and quality assurance requirements over and above those needed for integration and safety purposes sometimes are added by the centers to ensure that experiments do not fail.

By shifting to a “customer support” mode of operation, NASA could greatly reduce the barriers to experimentation on the ISS. In this mode, the primary responsibility for the success of an experiment would be placed on the experimenter. Instead of creating and enforcing additional requirements, NASA would assist ERTD experimenters in meeting ISS integration and safety requirements and overcoming the technical difficulties involved in space experimentation. Experimenters could then focus their attention on ensuring that the experiment performs properly.

One of the most important tools that NASA could provide to assist experimenters would be a database containing:

• information on hardware (such as batteries, computers, and other modular, off-the-shelf items) that has been used successfully in previous space experiments

• “best practices” information gleaned from previous experiments

• information on the ISS integration process

• phone numbers and e-mail addresses of “matchmakers” who can link experimenters with experts (inside and outside NASA) on various phases of space experiment design

• lessons learned about the causes of previous problems and failures

Experimenters who use the Space Shuttle must follow three integration paths to prepare an experiment for flight. These are (1) payload integration, including procedures, stowage, and mission operations issues, (2) interface control, including verification tests and analyses, and (3) the safety process. Experimenters typically work through these processes in consultation with a NASA center. There is, however, no published guide to lead experimenters through these processes, and every NASA center has different rules for the integration paths.

This arrangement has led to confusion and difficulties for experimenters. Experiments designed to meet the integration requirements of one center sometimes need to be modified to meet a slightly different set of requirements when responsibility for the experiment shifts to another center. Similarly, investigators familiar with the procedures of one center may have to learn a new set of procedures when they work with another center. A third problem is caused by the internal NASA process in which space platform resources (principally

electric power, volume, and crew time) are reallocated from one NASA center or organization to another. In such cases, a center may set aside additional reserves on top of the platform's initial reserves, thereby reducing the resources available to experimenters. (The additional reserves are sometimes referred to as “nested reserves.”)

The integration process could be simplified by standardizing and publishing the integration regulations for experiments on the ISS. Ideally, these regulations would be available electronically to all potential experimenters and would incorporate commercial standards when appropriate. (As is discussed later, acceptance of commercial standards would allow experimenters to use a larger variety of off-the-shelf equipment, potentially greatly reducing the costs of experimentation.)

Experimenters have also pointed out that integration rules—particularly safety rules—are sometimes rigidly applied even in cases where no safety hazard is apparent. For example, NASA wanted investigators conducting a recent shuttle experiment to perform analyses to determine if a laser pointer might become dangerously hot, even though innumerable similar laser pointers are used regularly on Earth without incident. Although waivers can sometimes be acquired, they are difficult to obtain, and there is no one to speak for experimenters in the decision-making process. One way to improve the situation might be to create an ombudsman who could be appealed to in such situations and who would have the ability to grant waivers when appropriate.

NASA also could consider centralizing the payload integration function in a single organization. This entity would provide a single contact point for payload integration for all ISS experimenters—including both outside experimenters and experimenters from within NASA. Such a change would bring together integration experts in a single location where experimenters could seek assistance, and it would also facilitate the development of standard requirements and reduce the “nested reserves ” problem. Optimally, the organization (which could be located within NASA or operated under contract by a private firm) would:

• develop, for the benefit of potential researchers, a database containing detailed descriptions of experimental apparatus, “best practices, ” and problems experienced in previous space ERTD research

• develop and disseminate a standard set of integration procedures, including safety rules

• function as an integration and safety ombudsman, ascertaining whether experiments meet safety and integration rules while guaranteeing protection of proprietary information

In more general terms, the organization would be responsible for assisting researchers in developing experiments for space, while allowing responsibility for the experiment's success to rest with the investigator.

Finding 6. ERTD researchers sometimes face unnecessary procedural obstacles in getting their experiments into space, and the degree of support provided to them by the NASA centers is uneven. ERTD would advance more effectively under a more standardized and customer-friendly regime.

The technical interfaces—including the payload accommodations, power supply, lab support equipment, and communications protocols—through which the ISS will provide support for experiments could be modified in a number of ways to facilitate ERTD. Potential modifications can be grouped into (1) modifications to ensure that the ISS's technical interfaces are similar to those in ground-based laboratories, and (2) modifications to provide accommodations and facilities to support ERTD. Although the focus here is on ERTD, some of these modifications would also facilitate the conduct of other types of experiments.

Although it is the unique features of the space environment that will make the ISS a valuable ERTD laboratory, investigators will find it much easier to study and utilize those unique features if, to the greatest degree feasible, the ISS's technical interfaces are similar to those of terrestrial laboratories. Such interfaces would allow experimenters to use a greater variety of off-the-shelf hardware, which is typically more reliable than the one-of-a-kind items that must be developed for unique interfaces. This would also reduce the researcher's unique hardware and nonrecurring engineering costs, and allow some elements of experiments to be duplicated easily on the ground for control and troubleshooting purposes. For example, if a modern industry-standard communications protocol (such as TCP/IP) were made available to transfer data to and from ISS experiments, experimenters would be able to use more off-the-shelf software to aid in experiment control, reducing the costs of experiments and probably improving their reliability. Of course, it would not be cost-effective to make all ISS interfaces similar to the interfaces in an Earth-based laboratory. For example, converting the DC power provided by the photovoltaic arrays to provide 110 or 220 volts of alternating current for all ISS experiments would mean a significant loss of energy from the planned 120 volts of direct current.

In a ground-based ERTD laboratory, nothing is permanent but the walls. Over time, facilities are replaced and new computers and instruments are brought in. If the ISS's technical interfaces are to be similar to those of ground-based laboratories for the duration of the station 's life, it will be necessary to upgrade the ISS laboratory equipment periodically. Although providing such upgrades would be an additional logistical burden, upgrades would improve ISS capabilities and reduce the need to develop specialized equipment designed to remain effective over the ISS's entire life. Rather than trying to design a video camera

that would be good for 15 years, for example, NASA might buy a new (and better and cheaper) camera off the shelf every three years or so.

One laboratory support system that clearly would benefit from regular upgrades would be the communications link between ISS experiments and experimenters on Earth. If the planned 33 international standard payload racks, 6 attached payloads, and JEM exposed facility were to downlink at 20 percent of their net capacity, the data rate required would be in excess of 1 Gbps. The centrifuge module, video sites, and downlinks for the support of remotely operated robotics will result in additional communications requirements. Even with data compression, it is clear that the planned 50 Mbps data rate will soon become inadequate. A pre-planned upgrade scenario might look like the plan in box 4-1. By developing similar upgrade plans for other laboratory support technologies in cooperation with users, NASA would ensure steady improvements in the experiment support capabilities of the ISS.

Finding 7. ERTD experiments on the ISS will be cheaper, easier to develop, and more reliable if investigators can use off-the-shelf components and consider the ISS an extension of their laboratories on Earth rather than a completely foreign environment. Maintaining this capability will require regular upgrades of ISS laboratory equipment.

As described in chapter 2, the ISS will have a variety of internal and external accommodations for experiments. The internal accommodations, however, were designed primarily to support life and microgravity science experiments and the external sites primarily to support remote sensing and astronomy. Supporting ERTD was usually only a secondary design goal, if that. Although many ERTD experiments would be able to use existing sites, others would need accommodations not included in the current ISS design.

One potential problem is the lack of sufficient external attach points capable of supporting ERTD experiments. (Currently planned sites are shown in figure 2-1.) Because experiments inside the ISS have been a major driver of station design, it appears that there are sufficient accommodations inside the ISS to support internal ERTD experiments. The availability of exterior sites, on the other hand, will be very limited, particularly during the station's first decade. This is especially restricting, since external attach points would be required for ERTD in a wide range of technical areas (discussed in chapter 3), including the effects of the space environment on various materials and components, advanced power systems, deployable and erectable structures, advanced propulsion systems, and thermal control. Thus, a vigorous program of ERTD might require additional external accommodations.

Another potential problem for ERTD is that, as currently designed, the ISS's external accommodations may not be large enough for a wide variety of experiments. Currently, none of the six attach sites on the station's truss has an operational envelope—the volume within which the experiment is allowed to operate—larger than 15 feet by 15 feet by 10 feet. This would not be large enough to support, for example, a large solar dynamic power technology demonstrator or to conduct tests of full-scale deployable structures. It might also be difficult to fit an advanced propulsion system testbed within such an envelope, since plumes from thruster firings would obviously travel well beyond the envelope boundaries. If these types of ERTD are to be performed on the ISS, the operational envelope at one or more external sites will have to be enlarged.

Many of the ISS payload accommodations for life and microgravity sciences experiments will contain large generic facilities, such as furnaces for melting materials and glove boxes for handling samples. Such facilities, which are designed to support a number of different experiments, can provide capabilities superior to those that can be achieved by individual experiments, and may permit reductions in the size and cost of the hardware required for the individual experiments that use the facilities. Such facilities, however, can also fall behind the state of the art, and can draw away resources that could otherwise be used to support innovative experiments in different fields. To avert these problems,

ERTD facilities should be modular, support a wide variety of experiments, and be upgradeable over time with new off-the-shelf software and hardware.

The ideal modular, upgradeable, and widely useful ERTD facility would be a “toolbox” containing a set of standard laboratory equipment to help in ERTD experimentation. This would reduce the amount of equipment that would have to be brought to orbit with each experiment and would improve experiment debugging and repair. Although NASA's Offices of Space Flight, and Life and Microgravity Sciences and Applications, have been developing sets of laboratory support equipment (including such items as a pH meter, specimen labels, a digital oscilloscope, a camera, and a multimeter) for their ISS research, a similar set has not yet been developed to support ERTD. Such a toolbox might include a data logger, instrumentation amplifiers, motor amplifiers, and voltage converters. A program to regularly replace outdated tools would be necessary to ensure that the ISS keeps pace with changes in ground-based laboratories.

A variety of other facilities could be developed to support ERTD on the ISS. Some would be similar to the facilities developed for non-ERTD experiments, while others would be more “virtual” facilities dispersed throughout the station to support ERTD experimentation. Some of the facilities expected to be valuable in supporting ERTD in various technical areas are discussed in chapter 3. These include a propulsion testbed, a fluid handling facility, a hard mount (or “back-stop”) for structural research, an attach point with point-and-track capability, and a materials exposure facility.

In addition to these, a number of more generic facilities could be developed to support a wide range of ERTD activities. A local differential GPS grid for the ISS, for example, would simplify many tasks involving moving objects close to the station, thus enabling superior “air traffic control” for nearby robots, shuttles, cargo modules, and free-flying platforms. The grid would ensure that uninterrupted GPS signals were available at all locations in and around the ISS. It would also improve EVA safety and would provide (using the emerging carrier-phase technology) the sub-centimeter accuracy location and orientation information required for a controlled environment for robotics activities onboard the ISS, thus reducing the crew time required to aid and oversee robotic activities. The hardware needs for such a system would be small: a GPS transmitter ensemble to provide a fixed point location grid relative to the space station's position, and a GPS receiver and cellular-type communications link to an intra-station network to relay the information.

By adding appropriate instrumentation, the ISS itself could be outfitted as an ERTD facility. As noted in chapter 2 and chapter 3, the assembly of the ISS will give researchers a significant opportunity to study the behavior of large structures in space, and the ongoing operations of the ISS will provide valuable information on the effects of space activities on the local environment. To acquire this data, however, the ISS must be suitably instrumented. Instrumentation strategies could involve building strain gages and accelerometers into the ISS structure, or bonding

reflectors onto the structure and using lasers to measure their movements, or some combination of the two methods. Pressure transducers could be placed on various parts of the ISS to measure the effects of shuttle orbiter thruster plumes, and sensors could be located around the ISS to detect the contamination caused by ISS outgassing and venting. Although it will be possible to attach such instruments to the station in space, it would be far easier to do so before the ISS is launched. Attaching instrumentation on Earth also would allow more complete data sets to be gathered.

Many smaller ERTD experiments would benefit greatly from a generic facility with simple interfaces that would allow more rapid integration than will be available elsewhere in the ISS. Some steps in this direction have already been taken through the development of express racks and pallets. (Figure 4-1 shows how an ISPR can be configured to function as an express rack.) Express racks will contain standard structural, power, thermal, waste gas, command, control, data, and video interfaces. Express pallets, which will be attached to the outside of the ISS, similarly are designed to simplify the integration process and to provide standard power, data, and mechanical interfaces. The express racks and pallets could become major workhorses for ERTD experimentation.

It is impossible to know the types of ERTD activities that experimenters will want to conduct 10 or 15 years from now or what type of laboratory support equipment or accommodations these activities will require. It is clear, however, that a broad spectrum of experiments requiring a variety of accommodations and support equipment may need to be conducted on the ISS, and that the costs of such experiments will be unnecessarily high if the capability to support them is not incorporated into the ISS before launch. Design modifications made now that would allow the ISS to support a wide range of future ERTD thus could result in significant long-term savings.

Although the overall design of the space station is in its last stages, many features of the detailed design could still be modified slightly to enhance the ISS's capabilities to support ERTD. Such modifications might include the printing of bar codes on external station elements to facilitate future robotic activity or the stringing of additional fiber-optic cables in the laboratory modules to allow the upgrading of communications capabilities. Chapter 3 suggests a number of facility and hardware modifications that could be incorporated into the ISS design, but detailed analysis must be performed to determine which of them are the most worthy to be implemented with the limited funds available.

Finding 8. One of the consequences of the historically low profile of ERTD research in the ISS program is that the needs of ERTD experimenters have had little impact on the design of the ISS. Although the ISS is in the last stages of

design, minor changes that would greatly facilitate the conduct of ERTD can still be implemented. A relatively small investment now could yield significant long-term payoffs for both the space program and the nation.

Recommendation 3. NASA should establish a single organization to work with researchers interested in conducting ERTD experiments on the ISS (and other space platforms). This organization should assist experimenters in developing experiments for space and in meeting safety and integration rules. The organization should also act as an integration and safety ombudsman for experimenters.

Recommendation 4. Technical interfaces between the ISS and experimenters should be examined to ensure that, except where differences are absolutely necessary, the interfaces are similar to the ones in ground-based laboratories. Off-the-shelf laboratory equipment, upgraded periodically, should be used wherever possible.

Recommendation 5. The NASA Administrator should immediately convene a rapid-response group to determine the highest-priority modifications (in terms of costs and benefits) to the ISS to support ERTD. One of the first things this group should do is to review the adequacy of plans to (1) instrument the ISS for structural dynamics and space environment research, and (2) embed fiber-optic cables throughout the ISS to facilitate future communications upgrades.